Treatment in pregnancy:
Chicken Pox Infection
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Immunized or Hx of past infection:
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exposure: nothing to do.
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simple rash: acyclovir 800mg PO 5x/day for 7 days
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severe infection or pneumonia, admit for IV acyclovir and supportive care.
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Not Immunized:
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exposure: consider VZIG, give first dose within 96 hours if possible, and up to 10 days from exposure.
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simple rash: acyclovir 800mg PO 5x/day for 7 days
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severe infection or pneumonia, admit for IV acyclovir and supportive care.
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Zoster (Shingles)
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acyclovir 800mg PO 5x/day for 7 days
Note:
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No role for VZIG if patient is immunized or has Hx of prior infection.
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VariZIG not proven to help once infection occurs, only in reducing chance of developing infection.
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Women should be immunized as soon as possible, preferably 1 month prior to becoming pregnant, or as soon as possible after delivery.
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VariZIG is given to pregnant non-immunized women who are exposed (legit exposure) with plans for vaccination after delivery.
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Acyclovir is given to anyone who is vaccinated and shows symptoms.
Background:
- Chickenpox is caused by the varicella-zoster virus, a member of the herpes family of viruses.
- Most people are exposed or immunized as children.
- Infection is less severe in children than adults and usually has less morbidity.
- The vaccine was introduced in 1995.
- Acute infections causes a rash of the fact-trunk- and extremities that causes macule-papule-then vesicles then crusting. Lesions appear over 4 days, crust by day 6 and slough off within a week or two.
- Prodrome includes fever, malaise, and myalgia one to four days prior to the onset of rash.
- Vaccination protects 98-99% of people after 2 doses.
- Those with varicella can pass it along more easily than those with zoster.
- People are infectious from 1-2 days prior to symptoms until all lesions have crusted over.
- Passage also occurs from exposure to secretions from mucus membranes in varicella, more so than with exposure to fluid in vesicles.
- Incubation is 10-21 days post exposure.
Epidemiology:
<2% of infections occur in adults >20 yo, about 25% of mortality is in this age group. 1 to 5 cases per 10,000 is the estimated incidence, but it isn’t reportable so exact numbers are unknown.
Complicatons:
Complications are more common in adults than children and include
- meningitis, encephalitis, cerebellar ataxia, pneumonia, glomerulonephritis, myocarditis, ocular disease, adrenal insufficiency, and death.
- Secondary bacterial infections can also occur in patients with significant cutaneous disease.
Mother:
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Maternal varicella during pregnancy is associated with the development of herpes zoster during infancy.
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Varicella infection immediately before or after delivery puts the baby at risk for neonatal varicella, which varies from mild rash to disseminated infection.
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Maternal zoster is generally not associated with fetal or newborn disease.
- Most common complication of varicella in pregnancy is pneumonia.
- There is an increased rate with varicella in pregnancy but the numbers have improved with antiviral therapy. It was reported as up to 20% experiencing pneumonia, but may be as low as 2.5% of cases now. Smoking and having >100 vesicles increases the risk.
- The pneumonia usually develops within one week of the rash
- The clinical course is unpredictable and may rapidly progress to hypoxia and respiratory failure.
- CXR findings include a diffuse or miliary/nodular infiltrative pattern
Fetus:
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Congenital Varicella Syndrome occurs in less than 2% of pregnancies where mom has primary varicella in the first 20 weeks.
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It is more rare after 20 weeks gestation.
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Only one published case report of this occurring due to zoster since 1987
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Congenital varicella syndrome includes limb hypoplasia, skin lesions, neurologic abnormalities, and structural eye damage.
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Mortality rate of 30 percent in the first few months of life.
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15 percent risk of developing herpes zoster by age 4.
References:
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Cytomegalovirus, parvovirus B19, varicella zoster, and toxoplasmosis in pregnancy. Practice Bulletin No. 151. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;125:1510–25.
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CDC, Prevention of Varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP) Direct Link
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Royal College of Obstetricians and Gynecologists, Chicken Pox In Pregnancy, Green-top Guideline No. 13, January 2015 Direct Download
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Enders G, Miller E, Cradock-watson J, Bolley I, Ridehalgh M. Consequences of varicella and herpes zoster in pregnancy: prospective study of 1739 cases. Lancet. 1994;343(8912):1548-51. PubMed
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Stone KM, Reiff-eldridge R, White AD, et al. Pregnancy outcomes following systemic prenatal acyclovir exposure: Conclusions from the international acyclovir pregnancy registry, 1984-1999. Birth Defects Res Part A Clin Mol Teratol. 2004;70(4):201-7.PubMed
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Cohen A, Moschopoulos P, Stiehm RE, Koren G. Congenital varicella syndrome: the evidence for secondary prevention with varicella-zoster immune globulin. CMAJ : Canadian Medical Association Journal. 2011;183(2):204-208. doi:10.1503/cmaj.100615. PubMed